ALBERT

Description: Despite the intensifying interest in flash drought both within the United States and globally, moist tropical landscapes have largely escaped the attention of the flash drought community. Because these ecozones are acclimatized to receiving regular, near-daily precipitation, they are especially vulnerable to rapid-drying events. This is particularly true within the Caribbean Sea basin where numerous small islands lack the surface and groundwater resources to cope with swiftly developing drought conditions. This study fills the tropical flash drought gap by examining the pervasiveness of flash drought across the pan-Caribbean region using a recently proposed criterion based on the evaporative demand drought index (EDDI). The EDDI identifies 46 instances of widespread flash drought “outbreaks” in which significant fractions of the pan-Caribbean encounter rapid drying over 15 days and then maintain this condition for another 15 days. Moreover, a self-organizing maps (SOM) classification reveals a tendency for flash drought to assume recurring typologies concentrated in one of the Central American, South American, or Greater Antilles coastlines, although a simultaneous, Caribbean-wide drought is never observed within the 40-yr (1981–2020) period examined. Furthermore, three of the six flash drought typol- ogies identified by the SOM initiate most often during Phase 2 of the Madden–Julian oscillation. Collectively, these find- ings motivate the need to more critically examine the transferability of flash drought definitions into the global tropics, particularly for small water-vulnerable islands where even island-wide flash droughts may only occupy a few pixels in most reanalysis datasets.

Description: Published

Description: Refereed

Description: Given the go ahead, deep-sea mining operations are likely to continue for decades on a substantial spatial scale and the resulting sediment plumes combined, are likely to extend beyond the licenced mining areas, and could lead to the chronic exposure of deep-sea organisms to a mixture of metals, even mobile species, such as fish, that could conceivably display avoidance behaviour. The metal concentrations, often substantially below lethal doses, mean that individual mortality is too blunt a measure to allow assessment of “serious harm”. Commonly used cellular biomarkers of exposure in ecotoxicology include DNA damage using the Comet assay. True deep-sea ecotoxicological studies with fish are rare and to our knowledge, there are no published data or method optimizations for deep-sea fish. Coryphaenoides ssp. were collected during SMARTEX expedition 1 (Feb/Mar, 2023) to the Clarion Clipperton Zone (CCZ) in the Eastern Pacific Ocean using a baited trap deployed between 4580–4,732m depth for 24–48 h. Blood and gill tissue were removed and processed for the Comet assay. In order to reduce artefactual DNA damage from cryopreservation observed previously, two sets of samples were prepared: a cryopreservative (10% DMSO) was added to one set of samples and stored at − 80 ◦C; the second set was used to perform a Comet assay within hours of collection. A custom-built gimble table enabled horizontal electrophoresis at sea after which Comet assay slides were dried and stored at room temperature until further analysis. The Comet assay was also assessed in freshly sampled and frozen rainbow trout cells as a proxy control in order to evaluate potential artefacts from the collection and sampling procedure of the deep-sea fish. The blood samples processed at sea had a significantly reduced level of DNA damage compared to the frozen samples. There was no significant difference between the fresh deep-sea and rainbow trout samples. However, the freshly prepared gill samples in Coryphaenoides ssp. showed substantial artefacts, possibly as a consequence of barotrauma. These results represent the first effort at establishing baseline DNA damage data for deep-sea fish, an essential component in understating and quantifying the impact of deep-sea mining.

Description: Published

Description: Refereed

Description: The global premodern descriptive catalogs of von Hoff (1840–1841), Perrey (1845–1850), and Mallet (1853–1855), all covering the period from Antiquity to 1842, have been used to populate the preinstrumental section of parametric catalogs since the late 1960s. The earthquake lists of these three authors have been individually analyzed to compile a comprehensive inventory of the sources on which they relied. Conversely to previous analyses and uses that were focused—primarily if not exclusively—on their seismological content, both in the compilation of the inventory and in this article the hundreds of items supplying earthquake records are in the foreground. After having merged these three sets of sources and having obtained a comprehensive list of about 5000 earthquakes and two times more source entries, similarities and differences are evidenced. This comprehensive analysis is meant to catch and explain how the preference given to one source among many available may have affected the interpretation of the collected records and influenced the accuracy and reliability of the earthquake lists by von Hoff, Perrey, and Mallet, and consequently of their contribution to the construction of the global modern parametric earthquake catalogs.

Description: Published

Description: 2456-2468

Description: OST2 Deformazione e Hazard sismico e da maremoto

Description: JCR Journal

Description: Turbulent energy transfer in nearly collisionless plasmas can be conceptualized as a scale-to-scale Langevin process. Hence, the statistics of magnetic field fluctuations can be embedded in the framework of stochastic process theory. In this work, we investigate the statistical properties of the pristine solar wind as observed by Parker Solar Probe by defining the cascade trajectories of magnetic field increments and by estimating the stochastic entropy variation along them. Through the stochastic entropy, we can identify two regimes where fluctuations exhibit contrasting statistical properties. In the inertial range, the entropy production is associated with an increase of the flatness indicating the occurrence of intermittency. Otherwise, trajectories associated with an entropy consumption exhibit global scale invariance. In the transition region toward ion scales, the phenomenology switches: entropy-consuming trajectories exhibit a sudden flatness increase, associated with the presence of small-scale intermittency, while entropy-producing trajectories display a nearly constant flatness. Results are interpreted in terms of physical processes consistent with an accumulation of energy at ion scales.

Description: Published

Description: L20

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: When the Kanto earthquake struck on Saturday the 1st of September 1923 at a few minutes to noon, the foreign residents from western countries in the harbour city of Yokohama reached 2,500, and a similar presence was in Tokyo, which as the capital hosted the officers of embassies, consulates, and trade companies. These foreign residents left impressive records of the earthquake occurrence, as well as the fire that started immediately after. To add a different viewpoint to the overall understanding of this earthquake disaster, we concentrated on the considerable quantity of documents now stored at the National Archives (Kew Gardens, UK) and at the Affaires Etrangéres-Archives diplomatiques (La Courneuve, France). These documents were produced by British and French diplomats and naval commanders as well as foreign residents of different nationalities who were in Yokohama and Tokyo at the time of the earthquake. The immediacy of the descriptions they contain and the details they supply about the earthquake, the fire, and the rescue and relief actions bring us back to the shaking and shocking moments experienced by the people living in Yokohama and Tokyo one hundred years ago.

Description: Published

Description: 598-610

Description: OST2 Deformazione e Hazard sismico e da maremoto

Description: JCR Journal

Description: We present a thorough implementation of the two-stage framework proposed in [A.Cicone, M.Huska, S.H.Kangand, S.Morigi, JOT:a Variational Signal Decomposition into Jump, Oscillation and Trend, IEEE Transactions on Signal Processing, 2022]. The method assumes as input a 1D signal represented by a finite-dimensional vector in RN. In the first stage the signal is decomposed into Jump (piece-wise constant), Oscillation, and Trend (smooth) components, and in the second stage the results are refined using residuals of other components. We propose an efficient numerical solution for the first stage based on alternating direction method of multipliers, and a solid algorithm for the solution of the second stage.

Description: Published

Description: 153–166

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: The near-Earth electromagnetic environment represents a far-from-equilibrium system characterized by sudden irregular energy relaxation events. For a broad class of complex systems, time series can be interpreted in terms of a superposition of stochastic and deterministic components occurring at different time scales. In this work we use the generalization of the SYM-H index provided by the SuperMAG collaboration (SMR), which is meant for monitoring the global variation of the horizontal component of the Earth’s magnetic field in the near-equatorial regions. The aim of this work is to model the SMR dynamics via stochastic differential equations thus providing a semi-empirical model whose parameters are retained from data. As a first step we test the Markov condition on the SMR data sample, which represents the basic condition for our stochastic modeling, and we show that such a requirement is accurately satisfied by SMR time series. This allows us to infer the model parameters for the SMR index through the Kramers–Moyal analysis. Finally, we give evidence that a purely diffusive process is not representative of the observed dynamics and then a model based on jump-diffusion processes must be considered to correctly reproduce the dynamical features of the SMR index.

Description: Published

Description: GM325

Description: OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorio

Description: JCR Journal

Description: The Iterative Filtering method is a technique aimed at the decomposition of non-stationary and non-linear signals into simple oscillatory components. This method, proposed a decade ago as an alternative technique to the Empirical Mode Decomposition, has been used extensively in many applied fields of research and studied, from a mathematical point of view, in several papers published in the last few years. However, even if its convergence and stability are now established both in the continuous and discrete setting, it is still an open problem to understand up to what extent this approach can separate two close-by frequencies contained in a signal. In this paper, first we recall previously discovered theoretical results about Iterative Filtering. Afterward, we prove a few new theorems regarding the ability of this method in separating two nearby frequencies both in the case of continuously and discrete sampled signals. Among them, we prove a theorem which allows to construct filters which captures, up to machine precision, a specific frequency. We run numerical tests to confirm our findings and to compare the performance of Iterative Filtering with the one of Empirical Mode Decomposition and Synchrosqueezing methods. All the results presented confirm the ability of the technique under investigation in addressing the fundamental “one or two frequencies” question.

Description: Published

Description: 128322

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: Current understanding of the kinetic-scale turbulence in weakly collisional plasmas still remains elusive. We employ a general framework in which the turbulent energy transfer is envisioned as a scale-to-scale Langevin process. Fluctuations in the sub-ion range show a global scale invariance, thus suggesting a homogeneous energy repartition. In this Letter, we interpret such a feature by linking the drift term of the Langevin equation to scaling properties of fluctuations. Theoretical expectations are verified on solar wind observations and numerical simulations, thus giving relevance to the proposed framework for understanding kinetic-scale turbulence in space plasmas.

Description: Published

Description: L042014

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: In the domain of space science, numerous ground-based and space-borne data of various phenomena have been accumulating rapidly, making analysis and scientific interpretation challenging. However, recent trends in the application of artificial intelligence (AI) have been shown to be promising in the extraction of information or knowledge discovery from these extensive data sets. Coincidentally, preparing these data for use as inputs to the AI algorithms, referred to as AI-readiness, is one of the outstanding challenges in leveraging AI in space science. Preparation of AI-ready data includes, among other aspects: 1) collection (accessing and downloading) of appropriate data representing the various physical parameters associated with the phenomena under study from different repositories; 2) addressing data formats such as conversion from one format to another, data gaps, quality flags and labeling; 3) standardizing metadata and keywords in accordance with NASA archive requirements or other defined standards; 4) processing of raw data such as data normalization, detrending, and data modeling; and 5) documentation of technical aspects such as processing steps, operational assumptions, uncertainties, and instrument profiles. Making all existing data AI-ready within a decade is impractical and data from future missions and investigations exacerbates this. This reveals the urgency to set the standards and start implementing them now. This article presents our perspective on the AI-readiness of space science data and mitigation strategies including definition of AI-readiness for AI applications; prioritization of data sets, storage, and accessibility; and identifying the responsible entity (agencies, private sector, or funded individuals) to undertake the task.

Description: Published

Description: 1203598

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: ESA's Swarm constellation entered in a “overfly” configuration in the period between September and October 2021, when the longitudinal distance between the lower pair and the upper satellite was at its minimum since the launch of the spacecrafts. In addition, the local time of the nighttime tracks was favorable to detect and study the morphology of post-sunset equatorial plasma bubbles (EPBs). In this study, we focus on the Swarm overfly occurring between 00:41 UT and 00:59 UT on 30 September 2021, which covered one of the most densely instrumented regions for the study of the ionospheric irregularities embedded in the EPBs: the South American sector. By exploiting the use of ground-based receivers of Global Navigation Satellite System (GNSS) signals in combination with the Swarm plasma density measurements, we study the irregularities in the EPB formed at ∼60°W and investigate the different scales of the irregularities and the cascading processes along the magnetic flux tubes. We also highlight how diffusion along the magnetic field lines occurs simultaneously with the plasma uplift, contributing then to the correct interpretation of the EPB evolution and decay process. The precious overfly conditions also allow the introduction of ionosphere-related quantities, evaluated across the tracks at satellite altitudes enlarging the possibilities given by the same quantities already available along the tracks. Such opportunity envisages the possibility to proxy the impact of EPBs on GNSS signals with Low-Earth Orbit satellite data provided by future missions specifically dedicated to the characterization of the near-Earth environment and ionospheric studies.

Description: Published

Description: e2022SW003331

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: The subduction of continental lithosphere is a complex process because the buoyancy of the crust is higher than the oceanic and should resist sinking into the mantle. Anyway, studies on the Alpine-Himalayan collision system indicate that a large portion of the continental crust is subducted, while some material is accreted in the orogens. The Apennine is a perfect case for studying how such processes evolve, thanks to high quality seismic images that illuminate a critical depth range not commonly resolved in many collisional settings. In this paper, we show the structure of the Apennines orogen, as jointly revealed by seismicity and deep structure from regional and teleseismic tomography and receiver function profiles. The westward subducting Adria lithosphere is well defined along the orogen showing a mid-crustal delamination. Seismicity within the underthrusting lower crust and velocity anomalies in the mantle wedge highlight how the subduction evolution is entangled with the liberation of fluids. The eclogitization of subducted material enhances the fluid release into the wedge, the delamination and retreat of the Adria plate. This delamination/subduction generates a coupled compression and extension system that migrates eastward following the retreat of the lithosphere, with broad sets of normal faults that invert or interfere with pre-existing compressional structures all over the roof plate. The sparseness and non-ubiquity of intermediate depth earthquakes along the subduction panel suggest that the brittle response of the subducting crust is governed by its different composition and fluid content. Therefore, the lower crust composition appears essential in conditioning the evolution of continental subduction.

Description: Published

Description: 1253443

Description: OST1 Alla ricerca dei Motori Geodinamici

Description: JCR Journal

Description: The study of the micro-meteoroid environment is relevant to planetary science and space weathering of airless bodies, as the Moon or Mercury. In fact, the meteoroids hit directly the surfaces producing impact debris and vapor, thus contributing to shape the exosphere of the planet. This work is focused on the study and modelling of the Mercury's Ca exosphere formation through the process of Micro-Meteoroids Impact Vaporization (MMIV). The MESSENGER/NASA mission provided measurements of Mercury's Ca exosphere, allowing the study of its configuration and its seasonal variations. The observed Ca exhibited very high energies, with a scale height consistent with a temperature 〉 50,000 K, originated mainly on the dawn-side of the planet. It was suggested that the originating process is due to MMIV, but previous estimations were not able to justify the observed intensity and energy. We investigate the possible pathways to produce the high energy observed in the Ca exosphere and discuss about the generating mechanism. The most likely origin may be a combination of different processes involving the release of atomic and molecular surface particles. We use the exospheric Monte Carlo model by Mura et al. (2007) to simulate the 3-D spatial distribution of the Ca-bearing molecule and atomic Ca exospheres generated through the MMIV process, and we show that their morphology and intensity are consistent with the available MESSENGER observations if we consider a cloud quenching temperature 〈 3750 K. The results presented in this paper can be useful in the exospheric studies and in the interpretation of active surface release processes, as well as in the exosphere observations planning for the ESA-JAXA BepiColombo mission that will start its nominal mission phase in 2026.

Description: Published

Description: 115616

Description: OSA3: Climatologia e meteorologia spaziale

Description: JCR Journal

Description: The Rhenish Massif in Central Europe, which includes the Eifel Volcanic Fields, has shown ongoing ground deformation and signs of possible unrest. A buoyant plume exerting uplift forces at the bottom of the lithosphere was proposed to explain such deformation; the hypothesis of (possibly concurrent) melt accumulation in the crust/lithospheric mantle has not been explored yet. Here, we test deformation models in an elastic half-space considering sources of varying aspect ratio, size and depth. We explore the effects of data coverage, noise and uncertainty on the inferred source parameters. We find that the observed deformation would require melt accumulation in sub-horizontal sill-like structures expanding at the rate of up to ∼0.045 km3/yr. We discuss feasibility, limitations and possible interpretations of our resulting models and elaborate on further observations which may help constrain the structure of the Rhenish Massif magmatic system.

Description: Deutsche Forschungsgemeinschaft (DFG)

Description: Published

Description: e2023GL105824

Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici

Description: JCR Journal

Description: Bromine monoxide (BrO) is a key radical in the atmosphere, influencing the chemical state of the atmosphere, most notably the abundance of ozone (O3). O3 depletion caused by the release of bromine has been observed and modeled in polar regions, salt pans, and in particular inside volcanic plumes. Furthermore, the molar ratio of BrO and SO2 – which can be detected simultaneously via spectroscopic measurements using the differential optical absorption spectroscopy (DOAS) method – is a proxy for the magmatic composition of a volcano and potentially an eruption forecast parameter. The detection of BrO in volcanic plumes from satellite spectroscopic observations is limited by the precision and sensitivity of the retrieval, which so far only allowed for the detection of BrO during major eruptions. The unprecedented spatial resolution of up to 3.5 km×5.5 km and the high signal-to-noise ratio of the TROPOspheric Monitoring Instrument (TROPOMI) on board Sentinel-5 Precursor (S-5P) enable observing and monitoring volcanic bromine release globally even for minor eruptions or even quiescent degassing. In this study, we investigate how far the BrO retrieval can be improved using TROPOMI data and how well BrO can be detected, even in small eruptions and during quiescent volcanic degassing. There are two steps for which improvements in accuracy are investigated and applied: the improvement and quantitative determination of (1) the detection limit of the DOAS BrO column retrieval and (2) the correction of the non-volcanic background BrO signal. First, the DOAS retrieval settings are varied, and their influence on accuracy and precision is investigated with respect to the detection limit and potential systematic influences. Based on these results, we propose a dedicated DOAS evaluation scheme optimized for the detection of BrO in volcanic plumes. For the DOAS retrieval, we propose the use of a large fit window from 323–360 nm, yielding a statistical uncertainty lower by a factor of 1.8 compared to previous BrO DOAS algorithms while not enhancing systematic influences. Second, the effect of the background BrO is reduced by a latitude-dependent empirical correction scheme correlated to cloud information as well as information on the O3 column. Via these improvements, the combined statistical and systematic uncertainties in the resulting BrO vertical column density is on the order of . We present a new and accurate retrieval algorithm of BrO columns from TROPOMI observations which allows for the detection of even slightly enhanced BrO amounts inside minor eruptive plumes of bromine-rich volcanoes. While designed specifically for TROPOMI observations, the retrieval algorithm is in general also applicable to other hyperspectral satellite observations. However, some parts might require adaptation.

Description: Published

Description: 5537–5573

Description: OSV3: Sviluppo di nuovi sistemi osservazionali e di analisi ad alta sensibilità

Description: JCR Journal

Description: 9 pages, 6 figures

Description: Many natural systems show emergent phenomena at different scales, leading to scaling regimes with signatures of deterministic chaos at large scales and an apparently random behavior at small scales. These features are usually investigated quantitatively by studying the properties of the underlying attractor, the compact object asymptotically hosting the trajectories of the system with their invariant density in the phase space. This multi-scale nature of natural systems makes it practically impossible to get a clear picture of the attracting set. Indeed, it spans over a wide range of spatial scales and may even change in time due to non-stationary forcing. Here, we combine an adaptive decomposition method with extreme value theory to study the properties of the instantaneous scale-dependent dimension, which has been recently introduced to characterize such temporal and spatial scale-dependent attractors in turbulence and astrophysics. To provide a quantitative analysis of the properties of this metric, we test it on the well-known low-dimensional deterministic Lorenz-63 system perturbed with additive or multiplicative noise. We demonstrate that the properties of the invariant set depend on the scale we are focusing on and that the scale-dependent dimensions can discriminate between additive and multiplicative noise despite the fact that the two cases have exactly the same stationary invariant measure at large scales. The proposed formalism can be generally helpful to investigate the role of multi-scale fluctuations within complex systems, allowing us to deal with the problem of characterizing the role of stochastic fluctuations across a wide range of physical systems.

Description: Published

Description: 023144

Description: OSA2: Evoluzione climatica: effetti e loro mitigazione

Description: JCR Journal

Description: We investigate effects of the three-dimensional (3D) structure of volcanic plumes on the retrieval results of satellite and ground-based UV–Vis observations. For the analysis of such measurements, 1D scenarios are usually assumed (the atmospheric properties only depend on altitude). While 1D assumptions are well suited for the analysis of many atmospheric phenomena, they are usually less appropriate for narrow trace gas plumes. For UV–Vis satellite instruments with large ground pixel sizes like the Global Ozone Monitoring Experiment-2 (GOME-2), the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) or the Ozone Monitoring Instrument (OMI), 3D effects are of minor importance, but usually these observations are not sensitive to small volcanic plumes. In contrast, observations of the TROPOspheric Monitoring Instrument (TROPOMI) on board Sentinel-5P have a much smaller ground pixel size (3.5 × 5.5 km2). Thus, on the one hand, TROPOMI can detect much smaller plumes than previous instruments. On the other hand, 3D effects become more important, because the TROPOMI ground pixel size is smaller than the height of the troposphere and also smaller than horizontal atmospheric photon path lengths in the UV–Vis spectral range. In this study we investigate the following 3D effects using Monte Carlo radiative transfer simulations: (1) the light-mixing effect caused by horizontal photon paths, (2) the saturation effect for strong SO2 absorption, (3) geometric effects related to slant illumination and viewing angles and (4) plume side-effects related to slant illumination angles and photons reaching the sensor from the sides of volcanic plumes. The first two effects especially can lead to a strong and systematic underestimation of the true trace gas content if 1D retrievals are applied (more than 50 % for the light-mixing effect and up to 100 % for the saturation effect). Besides the atmospheric radiative transfer, the saturation effect also affects the spectral retrievals. Geometric effects have a weaker influence on the quantitative analyses but can lead to a spatial smearing of elevated plumes or even to virtual double plumes. Plume side-effects are small for short wavelengths but can become large for longer wavelengths (up to 100 % for slant viewing and illumination angles). For ground-based observations, most of the above-mentioned 3D effects are not important because of the narrow field of view (FOV) and the closer distance between the instrument and the volcanic plume. However, the light-mixing effect shows a similar strong dependence on the horizontal plume extension as for satellite observations and should be taken into account for the analysis of ground-based observations.

Description: Published

Description: 1609–1662

Description: OSV3: Sviluppo di nuovi sistemi osservazionali e di analisi ad alta sensibilità

Description: JCR Journal

Description: The cave system in the Sierra de Atapuerca holds one of the most important archaeological sites for the understanding of early human occupation in Europe. Among the different cavities and galleries, the Gran Dolina cave yielded a new hominin species coined as Homo antecessor of an Early Pleistocene age. Encouraged by our previous results in Gran Dolina, we carried out a study to extend and deepen our rockmagnetic investigation of the paleoenvironmental reconstruction of the upper Gran Dolina cave based on experiments that include composition, relative concentration, and grain size of the magnetic iron oxides present in the sediments. Based on the rockmagnetic experiments, we identified magnetite, hematite, goethite, and possibly maghemite in changeable amounts along the profile, which allows us to complement the existing shortage in the literature on the palaeoenvironmental reconstruction of the site. We tentatively interpret the rockmagnetic changes recorded in the cave sediments in terms of glacial/interglacial conditions, furnishing the base for a better understanding for the formation conditions of this unprecedented archaeological site.

Description: Published

Description: 4580

Description: OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorio

Description: JCR Journal

Description: Laser interferometry enables to remotely measure microscopical length changes of deployedtelecommunication cables originating from earthquakes. Long reach and compatibility with datatransmission make it attractive for the exploration of both remote regions and highly-populated areaswhere optical networks are pervasive. However, interpretation of its response still suffers from a limitednumber of available datasets. We systematically analyze 1.5 years of acquisitions on a land-basedtelecommunication cable in comparison to co-located seismometers, with successful detection ofevents in a broad magnitude range, including very weak ones. We determine relations between acable’s detection probability and the events magnitude and distance, introducing spectral analysis offiber data as a tool to investigate earthquake dynamics. Our results reveal that quantitative analysis ispossible, confirming applicability of this technique both for the global monitoring of our planet and thedaily seismicity monitoring of populated areas, in perspective exploitable for civilian protection

Description: Published

Description: 178

Description: OST2 Deformazione e Hazard sismico e da maremoto

Description: OST5 Verso un nuovo Monitoraggio

Description: JCR Journal

Description: Interpreting the signal deriving from interferometric synthetic aperture radar (InSAR) analyses in volcanic islands, characterized by strong regional deformations and recurrent seismicity, is a complex and challenging issue. In these zones, the secondary effects connected to the SAR acquisition system cannot be neglected, and it is important to consider that delay phenomena of the electromagnetic waves, due to the propagation in the tropospheric layer and loss of SAR coherence because of dense vegetation, could affect the interferometric phase. This work focuses on Pico, the second largest and the youngest island of the Azores Archipelago (North Atlantic Ocean). This island consists of a central volcano and a fissure zone. These systems are inactive but recurrent microseismicity occurs in a rock volume host- ing a partially crystallized magma storage system, which fed the recent activity of the central volcano. In the same area affected by microseismicity, the main volcanic edifice shows flank instability. All these elements support the hypothesis of possible reactivation of the shallow magmatic system. Aiming to check potential active ground displacements and to define their source, we collected two datasets of C-band Sentinel-1 SAR data, both in descending and ascending acquisition geometry, from January, 2017, to December, 2020. The application of the small baseline subset method of differential InSAR allowed drawing the mean ground velocity maps over the island and the displacement time series, useful to understand the defor- mation evolution. InSAR data only evidence areas affected by small-scale subsidence at the cinder cones of the fissure zone and along the southeastern slope of Pico volcano, where local debris flows activate during rainy periods.

Description: Published

Description: 032402

Description: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici

Description: JCR Journal

Description: We investigate the seismic structure of the mantle wedge of the Apennines subduction zone (Central Mediterranean) using teleseismic receiver function (RF). We inverted RF for both isotropic and anisotropic properties of the mantle wedge, from below the overriding Moho to the “plate boundary”, i.e. the interface that separate the slab from the mantle wedge. Given the distribution of the seismic network, we are able to map out the change in the elastic properties at the transition between southern apennines and the Calabrian arc, given by the change in the subduction style (i.e from the subduction of continental materials to oceanic plate). We found that the anisotropy in the mantle wedge is similar between all seismic stations, generally highly anisotropic (〉 10%), with a direction of the symmetry axis that rotates clockwise from North to South, following the Calabrian arc geometry and likely indicating the mantle flow driven by the slab retreat. The elastic properties of the subducted crust are more heterogeneous. To the North, the subducted crust shows a highly anisotropic (〉 10%) behavior, and it occurs at larger depth (around 70 km depth), where to the South anisotropy is less intense (around 7%) and the subducted crust is shallower (around 60 km depth). These results point out a change in the subduction style that can be given by either a change in the metamorphic phase (more evolved blueschist facies stage to the North, initial greenschist facies stage to the South) or a different origin for the subducted materials (continental to the North and oceanic to the South). The differences in the anisotropic behavior of the subducted crust are reflected in the topography of the plate boundary, which becomes shallower from North to South, suggesting the existence of either a step in the slab topography or a more gentle ramp.

Description: Published

Description: 102004

Description: OST1 Alla ricerca dei Motori Geodinamici

Description: JCR Journal

Description: The implications of the COVID-19 outbreak are subjected to an increasing number of studies. So far, air quality trends related to the lockdown due to the pandemic have been analysed in large cities or entire regions. In this work, the region studied is the metropolitan area of Cagliari, which is the main city on the island of Sardinia (Italy) and can be representative of a coastal city that includes industrial settlements. The purpose of the study is to evaluate the effect of restrictions related to the COVID-19 outbreak on air quality levels and the traffic dynamics in this type of urban area. Nitrogen Dioxide (NO₂) levels before, during and after COVID-19 lockdown have been investigated using data acquired from the Sentinel-5P/TROPOMI satellite combined with on-site measurements. Both TROPOMI detected and ground-based data have revealed higher levels of NO₂ before and after the lockdown, compared to those during the period of COVID-related restrictions, in particular in the urban area of Cagliari. On the other hand, NO2 registered in the oil refinery area did not show significant differences associated with lockdown. The correlation of TROPOMI NO₂ tropospheric column with ground data (surface NO2) on a monthly mean basis showed different values based on the background and the highest Pearson's coefficient was of about 0.78 near to the city centre, where traffic can be considered a significant source of emission. In addition, a comparison of the air pollution level with the dynamics of vehicle traffic was investigated. The study highlighted a remarkable correlation between the reduction of the number of vehicles and the corresponding tropospheric NO₂ values that decreased on a weekly mean basis.

Description: Published

Description: 165464

Description: OSA2: Evoluzione climatica: effetti e loro mitigazione

Description: JCR Journal

Description: Earthquake is a complex and multivariate problem. Using a single parameter to extract anomalies is difficult to completely and truly reflect the preparation activity before earthquakes. In this paper, we develop a fusion anomaly extraction method based on principal component analysis (PCA) and non-negative tensor decomposition (NTD). It extracts anomalies by combining features of different parameters, which can obtain earthquake-related signals from dataset and reveal some weak anomalies hidden in individual parameters. By PCA-NTD, we fused the electron density and magnetic field data from the Swarm satellites to explore the possible precursors of 2021 M7.3 Maduo earthquake and compared the results with those of the single-parameter analyses. The cumulative value of fusion anomalies indicates two acceleration stages before the mainshock: from -51 to -24 days, following a sigmoid trend, and from -21 to the earthquake occurrence, following a power-law behavior. The second acceleration is more pronounced than the first one, and its critical point occurs near the date of the Maduo earthquake. Spatially, these anomalies are located around important fault zones (Altun fault, Jiali fault, and Red River fault) and the epicenter region, which likely reflect the northward stress and eastward stress experienced in the seismogenic area before the mainshock. As the earthquake approaches, the anomalies become more concentrated and closer to the impending epicenter. Furthermore, the ionospheric anomalies correspond well with the anomalous phenomena of lithospheric activity and atmospheric thermal radiation, which support a multi-channel lithosphere-atmosphere-ionosphere coupling (LAIC).

Description: Published

Description: 2002424

Description: OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impatto

Description: JCR Journal

Description: The relationship between the magnitude of earthquakes and their spatial and temporal distribution has been observed to exhibit a scale invariance hypothesised to originate from self-organized critical regimes. However, the fractality of earthquake distributions has been mostly established in circumscribed areas, despite the fact that the self-organized criticality of the lithosphere should only emerge at global or continental level. Here, we analyze seismic observations occurring over the whole Earth between 2004–2020 to investigate the fractal correlation dimension of earthquakes distribution. We find that the distribution of earthquakes is fractal on a global scale, as well as approximately magnitude-independent and stationary over decadal time scales. Our results set a primary constraint on the spatial scaling properties of lithosphere dynamics. We suggest that macroscopic models should fulfil this constraint to correctly replicate the features of seismicity, and potentially improve seismic hazard assessment.

Description: Published

Description: 146

Description: OST4 Descrizione in tempo reale del terremoto, del maremoto, loro predicibilità e impatto

Description: JCR Journal

Description: This study presents data and preliminary analysis from a temporary seismic network (SPQR), which was deployed in the urban area of Rome (Italy) for three months in early 2021. The network was designed to investigate the city’s subsurface while evaluating the feasibility of a permanent urban seismic network, and consisted of 24 seismic stations. Despite significant anthropogenic noise, the SPQR network well recorded earthquake signals, revealing clear spatial variability referable to site effects. In addition, the network’s continuous recordings allowed the use of seismic noise and earthquake signals to derive spectral ratios at sites located in different geological and lithological settings. During the experiment, there were periods of activity restrictions imposed on citizens to limit the spread of COVID‐19. Although the observed power spectral density levels at stations may not show visible noise reductions, they do cause variations in calculated spectral ratios across measurement sites. Finally, a statistical noise analysis was conducted on continuous seismic station data to evaluate their performance in terms of detection threshold for earthquakes. The results indicate that all network stations can effectively record earthquakes with a good signal‐to‐noise ratio (≥5 for P and S phases) in the magnitude range of 1.9–3.3 at distances of 10 km and 80 km, respectively. In addition, the network has the potential to record earthquakes of magnitude 4 up to 200 km, covering areas in Central Italy that are far from the city. This analysis shows that it is possible to establish urban observatories in noisy cities such as Rome, where hazard studies are of particular importance due to the high vulnerability (inherent fragility of its monumental heritage) and exposure.

Description: The experiment was financed with funds of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) dedicated to the institution’s open research projects (RicercaLibera) to promote free research within the INGV (Research Project: Three-dimensional shear-wave velocity imaging by ambient seismic noise tomography in the urban area of Rome city - Central Italy)

Description: In press

Description: OST5 Verso un nuovo Monitoraggio

Description: JCR Journal

Description: Archaeological sites may be exposed to different types of risks related to wars, natural phenomena, and illicit human activities. Quantitative data on the type and extent of the damages and destructions suffered by these sites are of primary importance for their reparation and the planning of conservation and defence actions. The Apurlec Monumental Archaeological Complex (about seventh–fourteenth century AD, Peru, “Intangible and Essential Heritage” of the Peruvian Ministry of Culture) includes platforms, canals, and rectangular ceremonial/administrative enclosures. Between June and August 2021, Apurlec has been affected by a partial destruction of its southern sector. Here we present the results of two UAV photogrammetric surveys conducted before (23 January 2021) and after (30 August 2021) the destructive event. The comparison of the orthoimages and the Digital Surface Models obtained form the two surveys allow us to detect illicit activities as earth removal to collect construction material, creation of cultivable areas, and steal manufacts from archeological excavations. We calculate that the area covered by the destruction is 121,665 m2 (perimeter of about 2 km2) the removed material amount to 401,513.5 m3, a value corresponding to a mass of about 702,648.63 ton. The post-destruction topography is lower of about 3.3 m with respect to the original one. Our anytical and metholodological approach could be extended to other archeological sites potentially exposed to anthropic and natural hazards.

Description: Published

Description: 110

Description: OSA2: Evoluzione climatica: effetti e loro mitigazione

Description: JCR Journal

Description: Accurate and traceable measurements are required to understand ocean processes, to address pressing societal challenges, such as climate change and to sustainably manage marine resources. Although scientific and engineering research has resulted in advanced methods to measure Essential Ocean Variables (EOVs) there is a need for cross comparison of the techniques and traceability to recognized standards. Metrological laboratories are experienced in accredited methods and assessment of methodology. An EU INFRAIA-02-2020: Integrating Activities for Starting Communities project MINKE (Metrology for Integrated marine maNagement and Knowledge-transfer nEtwork https:// minke.eu) brings European marine science and metrology Research Infrastructures together to identify synergies and create an innovative approach to Quality Assurance of oceanographic data. Quality depends both on the accuracy (that can be provided through the metrology component) and the completeness of the data sets. The collaboration between different Marine Research Infrastructures (RIs) places a fundamental role on assuring the completeness of the datasets, particularly at global scales. The MINKE project encourages enhancement through collaboration of national metrology laboratories and the oceanographic community. Metrological assessment of the accuracy and uncertainties within multidisciplinary ocean observations will provide data that are key to delivering policy information. Objectives across all the RIs are to facilitate ocean observation and build wider synergies. MINKE will investigate these synergies, then introduce metrology to the core of various EOV measurements. Currently the marine RIs cover laboratory and field operations, from the surface seafloor, coastal waters to deep sea, fixed ocean stations to ship and autonomous vehicle operations to ships of opportunity, and flux stations focusing on carbonate system variables. The nexus of these operations is the focal point for coordinated improvement of ocean observing methods. Measurement intercomparisons, traceability and uncertainty assessments should be at the core of the scientific observations. Specifically, MINKE will work with RIs and Metrology Institutes to improve the quality of dissolved oxygen, carbonate system, chlorophyll-fluorescence, ocean sound and current meter measurements, through access to metrology laboratories, Transnational Access and intercomparison studies across existing marine consortia and RIs. MINKE will also promote the development of absolute salinity observation, and improvements in marine litter measurements.

Description: The authors declare financial support was received for the research, authorship, and/or publication of this article. This paper was a milestone within the MINKE project, which has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement 101008724 and under the grant agreement no. 731031(EMSO-link, https://cordis.europa. eu/project/id/731036). SH’s time was also covered by the UK Natural Environment Research Council Climate. Linked Atlantic Section Science (CLASS) project (NE/R015953/1) and iFADO project (Innovation in the Framework of the Atlantic Deep Ocean), which was supported with ERDF funds from the INTERREG Atlantic Area Programme under contract EAPA 165/2016 and grant agreement no. 862923 (AtlantECO, Atlantic Ecosystems Assessment, Forecasting & Sustainability). ICM-CSIC acknowledges the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S). PLG was supported by TechOceanS project, which received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101000858. This output reflects only the author’s view, and the Research Executive Agency cannot be held responsible for any use that may be made of the information contained therein.

Description: Published

Description: 1192030

Description: OSA4: Ambiente marino, fascia costiera ed Oceanografia operativa

Description: JCR Journal

Description: The ocean regulates the exchange, storage of carbon dioxide, plays a key role in global control of Earth climate and life, absorbs most of the heat excess from greenhouse gas emissions and provides a remarkable number of resources for the human being. Most of the geo-hazards occur in oceanic areas. Thus, high-quality systematic observations are necessary tools for improving our understanding, and subsequent assimilation to provide early warning systems. A holistic scientific approach for the understanding of the ocean's interrelated processes requires coordinated and complementary monitoring and observation programmes. Research Infrastructures (RIs) are large-scale facilities that provide resources and services for the scientific communities to conduct high-level research and foster innovation. RIs benefit from strong governance and multi-annual funding from their member states with operational life spans in decades. RIs promote knowledge, outreach and education to public, private, and policy stakeholders, and they play a key role in enabling and developing research in all scientific domains and currently represent a growing share of coordinated investment in research, and also in providing essential observations to operational services such as Copernicus. They are strategically important for Europe to lead a global movement towards a data-driven, interconnected, open digital twin that brings together different disciplines, clean technologies, public and private sectors and a broad scientific/technological community, as well as education and training. In Europe several marine RIs have been established, which are maintained by national and European Union (EU) resources. The aims of these infrastructures are aligned with the key priorities of the UN Decade of Ocean Science for Sustainable Development; and with the new European Research Area (ERA) Policy Agenda annexed to the Council conclusions on the ERA governance , which set out 20 concrete actions for 2022-2024 to contribute to the priority areas defined in the EU Pact for R&I . The purpose of this paper is to demonstrate that the combined expertise and assets of Europe’s marine RIs can form a comprehensive and holistic framework for long-term, sustainable integrated marine observation. Through this integration process the marine RIs can become better and better a significant pillar of the European Ocean Observing System (EOOS). Such a framework must be built as part of interfaces of interaction and promote not only scientific excellence but also innovation at all levels.

Description: Euro-Argo RISE Funded by the EU Horizon 2020 research and innovation programme under grant agreement n°824131. Euro-Sea: Funded from the EU Horizon 2020 research and innovation programme under grant agreement n°862626. ENVRI-FAIR: Funded from the EU Horizon 2020 research and innovation programme under grant agreement no824068. Additionally, the authors gratefully acknowledge the support of their home institutions.

Description: Published

Description: 1047251

Description: OSA4: Ambiente marino, fascia costiera ed Oceanografia operativa

Description: JCR Journal

Description: Albedo – the reflectivity of a surface - is an important component in the energy budget, impacting the local to global climate. Data from nadir-viewing satellites can be combined with bidirectional reflectance distribution function (BRDF) data from multi-angular observation platforms to achieve realistic albedo values that acknowledge anisotropy. In my thesis, I evaluated how the land surface albedo varied on spatial and temporal scales during the snow-free period on Disko Island, Greenland. I examined how the albedo differed among the vegetation classes. Concerning the methodology, I assessed how the combination of MODIS BRDF data with Landsat 8 (L8) or Sentinel-2 (S2) influenced the albedo. The study area was located at the southern tip of Disko Island (69.27 °N, -53.47 °E) in West Greenland and covered a wetland and a range of tundra vegetation. I analysed automatic weather station (AWS) data from 2013 to 2022 and conducted mobile albedo measurements in August and September 2022 to examine the temporal and spatial variability. For the period from June to September 2022, I derived the L8 and S2 based albedo with inclusion of MODIS BRDF and narrow to broadband conversion and analysed their variability with regard to vegetation classes. In the snow-free period, the albedo increased from a monthly mean of 0.16 in June to 0.19 in September in the AWS data. The mobile measurements ranged from 〈 0.10 above bare soil and water to 〉 0.23 above areas dominated by lichen, Salix glauca or Equisetum arvense. The satellite-based albedo revealed temporally variable, significant correlations to normalised difference vegetation and moisture indices that reached values 〉 0.5 in the fen and wet heath class on several days. The albedo of shrubs was not notably smaller than other vegetation types but partly 0.01-0.05 above them in both the mobile measurements and the satellite-derived albedo. This finding challenges the assumption that shrubification causes climate forcing in all circumstances. The albedo of L8 and S2 differed to each other and the local data (root-mean-square error 0.04-0.14). The BRDF correction increased the albedo by 0.01 on average compared to nadir reflectance. L8 was better in reproducing the expected temporal and spatial variability of albedo than S2, which displayed less variability. S2 seemed to be more sensitive to atmospheric effects of haze and clouds influencing albedo. Thus, L8 seemed more suitable to calculate albedo in the study area. Though there were some methodological limitations, this thesis highlights aspects that should be considered when analysing albedo or jointly using L8 and S2 in high latitude regions.

Description: Thriving in both epipelagic and mesopelagic layers, Rhizaria are biomineralizing protists, mixotrophs or flux-feeders, often reaching gigantic sizes. In situ imaging showed their contribution to oceanic carbon stock, but left their contribution to element cycling unquantified. Here, we compile a global dataset of 167,551 Underwater Vision Profiler 5 Rhizaria images, and apply machine learning models to predict their organic carbon and biogenic silica biomasses in the uppermost 1000 m. We estimate that Rhizaria represent up to 1.7% of mesozooplankton carbon biomass in the top 500 m. Rhizaria biomass, dominated by Phaeodaria, is more than twice as high in the mesopelagic than in the epipelagic layer. Globally, the carbon demand of mesopelagic, flux-feeding Phaeodaria reaches 0.46 Pg C y〈jats:sup〉−1〈/jats:sup〉, representing 3.8 to 9.2% of gravitational carbon export. Furthermore, we show that Rhizaria are a unique source of biogenic silica production in the mesopelagic layer, where no other silicifiers are present. Our global census further highlights the importance of Rhizaria for ocean biogeochemistry.

Description: Most earth system models (ESMs) neglect climate feedbacks arising from carbon release from thawing permafrost, especially from thawing of subsea permafrost (SSPF). To assess the fate of SSPF in the next 1000 years, we implemented SSPF into JSBACH, the land component of the Max Planck Institute Earth System Model (MPI-ESM). This is the first implementation of SSPF processes in an ESM component. We investigate three extended scenarios from the 6th phase of the Coupled Model Intercomparison Project (CMIP6). In the 21st century only small differences are found among the scenarios, but in the upper-end emission scenario SSP5-8.5 (shared socio-economic pathway), especially in the 22nd century, SSPF ice melting is more than 15 times faster than in the pre-industrial period. In this scenario about 35ĝ% of total SSPF volume and 34ĝ% of SSPF area are lost by the year 3000 due to climatic changes. In the more moderate scenarios, the melting rate maximally exceeds that of pre-industrial times by a factor of 4, and the climate change induced SSPF loss (volume and area) by the year 3000 does not exceed 14ĝ%. Our results suggest that the rate of melting of SSPF ice is related to the length of the local open-water season and thus that the easily observable sea ice concentration may be used as a proxy for the change in SSPF.

Description: Eine effektive Methode für die Interpretation verschiedener geophysikalischer Daten ist die kombinierte Auswertung der unterschiedlichen Messungen. Eine wichtige Grundlage für die kombinierte Auswertung seismischer und gravimetrischer Daten sind empirische Korrelationsbeziehungen zwischen der seismischen Geschwindigkeit und der Dichte. In Regionen mit extrem großen Krustenmächtigkeiten und hohen Temperaturen läßt sich mit bekannten Geschwindigkeit-Dichte-Relationen kein übereinstimmendes Modell aus den seismischen und gravimetrischen Daten ableiten. Auf der Basis von in der Literatur veröffentlichten Labordaten wurde das Verhalten der Dichte und der seismischen Geschwindigkeit von kristallinen Gesteinen unter dem Einfluß von Druck und Temperatur systematisch untersucht. Die Untersuchungen beinhalten auch den Temperaturbereich der partiellen Aufschmelzung der verschiedenen Gesteine. Druck und Temperatur haben einen entgegengesetzten Effekt auf die seismische Geschwindigkeit. Druckerhöhung bewirkt im allgemeinen eine Zunahme der Geschwindigkeit, Temperaturerhöhung führt zu einer Erniedrigung. Bei Erreichen der Schmelztemperatur wird eine drastische Geschwindigkeitsabnahme beobachtet, die bis über 50% betragen kann. Der Einfluß von Druck und Temperatur auf das Verhalten der Dichte ist, im Vergleich zur Geschwindigkeit, sehr viel geringer. Bei Temperaturerhöhung bis zur partiellen Aufschmelzung werden Dichteänderungen von unter 5% beobachtet. Um eine ausreichende Anzahl von Daten für die Entwicklung einer temperaturabhängigen Geschwindigkeit-Dichte-Relation zur Verfügung zu haben, wird aus den vorhandenen Labordaten das Verhalten der Geschwindigkeit unter extremen Temperaturbedingungen mit Hilfe von Modellrechnungen extrapoliert. Auf der Basis der vorhandenen chemischen Analyse wird für verschiedene Gesteine die initiale Schmelztemperatur und der Anteil der Schmelze bestimmt. In einem weiteren Schritt wird mit Hilfe eines einfachen Modellansatzes die Änderung der Geschwindigkeit bei partieller Aufschmelzung berechnet. Aus den so gewonnenen Daten wird eine temperaturabhängige Geschwindigkeit-Dichte-Relation und eine Geschwindigkeit-Dichte-Relation in Abhängigkeit des Schmelzanteils abgeleitet. Für die kombinierte Auswertung von seismischen und gravimetrischen Profildaten wurde ein Programmsystem zur Umrechnung von Raytracing-Geschwindigkeitsmodellen in Dichtemodelle geschrieben. Für die Umrechnung können verschiedene Geschwindigkeit-Dichte-Relationen benutzt werden. Das Dichtemodell kann über eingebundene Optimierungsalgorithmen an die gemessene Schwerekurve angepaßt werden. Die Anwendung der temperaturabhängigen Korrelationsbeziehungen zwischen Dichte und Geschwindigkeit wird am Beispiel von gravimetrischen und seismischen Profildaten aus dem Bereich der zentralen Anden zwischen 21° S und 24° S vorgestellt. Die Profildaten kreuzen einen Krustenbereich des Andenorogens, der von einem extremen Schwereminimum und einer großen Krustenmächtigkeit geprägt ist. Geothermische Modellrechnungen ergeben extreme Temperaturverhältnisse im Tiefenbereich der mittleren und unteren Kruste. Das refraktionsseismische Modell der andinen Kruste zeigt ausgeprägte Zonen erniedrigter Geschwindigkeit (LVZ) in der mittleren und unteren Kruste. Die niedrigen Geschwindigkeiten, verbunden mit der extremen Krustenmächtigkeit ergeben bei der Umrechnung der refraktionsseismischen Modelle in Dichtemodelle mit normalen Geschwindigkeit-Dichte-Relationen eine deutliche Überkompensation des Schwereminimums. Mit der temperaturabhängigen Geschwindigkeit-Dichte-Relation läßt sich eine gute Anpassung an die gemessene Schwerekurve erreichen. Mit dem Ergebnis der Anpassung kann der Grad der partiellen Aufschmelzung der andinen Kruste bestimmt werden. Der Anteil der partiellen Schmelze in den LVZ der Kruste im Bereich unter der Westkordillere kann, abgeleitet aus den Modellrechnungen, bis zu 20% betragen.

Description: thesis

Description: DFG, SUB Göttingen

Description: Zur Untersuchung der Krustenstruktur der Zentralen Anden ist in den Jahren 1982 bis 1989 ein Netz von größtenteils gegengeschossenen refraktionsseismischen Profilen vermessen worden, deren Auswertung und Interpretation Gegenstand dieser Arbeit ist. Die abgeleiteten Krustenstrukturen und -mächtigkeiten wurde durch eine tektonische Bilanzierung modelliert. Aus den drei in N-S Richtung verlaufenden Profilen in der Küstenkordillere, der Präkordillere und auf der argentinischen Puna, drei W-E Profilen von der Küste bis zur Puna (24°S), bis zur Westkordillere (22 °S) und über das gesamte Andenorogen bis zum Chaco in Bolivien (21 °S), sowie von der Kupfermine Chuquicamata ausgehenden Profilen und einer Fächerbeobachtung, wurde eine starke Variation der Kruste sowohl in vertikaler als auch in horizontaler Richtung abgeleitet. Eine deutliche Diskontinuität in 40 km Tiefe unter der Küstenkordillere wird als Moho der subduzierten ozeanischen Nazca Platte interpretiert. Sie taucht nach Osten ab und läßt sich in den refraktionsseismischen Beobachtungen bis zum chilenischen Längstal und möglicherweise bis zur Präkordillere verfolgen. Eine eindeutige Interpretation der Diskontinuitäten in 50-55 km Tiefe unter dem Längstal und in 60-70 km Tiefe unter der Präkordillere ist allerdings nicht möglich. Es kann sich hier um die ozeanische Moho oder abgeschuppte Teile davon oder um eine, möglicherweise in Bruchstücken vorhandene, kontinentale Moho handeln. Die kontinentale Kruste im Forearc zeigt im Westen eine sehr hohe Durchschnittsgeschwindigkeit von 6.6 km/s, die bis zur Präkordillere auf 6.2 km/s abfällt. Die Mächtigkeit steigt von 30 km in der Küstenkordillere auf 60-70 in der Präkordillere an. Es kann eine Unterteilung in eine durch hohe seismische Geschwindigkeiten gekennzeichnete obere und mittlere Kruste, die die mesozoische Kruste in diesem Bereich repräsentiert, und eine tiefere Kruste, überwiegend durch Zonen geringer Geschwindigkeit (LVZ) geprägt, vorgenommen werden. In der östlich angrenzenden Westkordillere, dem heutigen magmatischen Bogen, sind nur auf dem südlichen Profil deutliche Anzeichen für eine Kruste/Mantel Grenze in 60 km Tiefe vorhanden. Weiter nördlich muß von einer starken Absorption der seismischen Wellen und daraus abzuleitender geringer Durchschnittsgeschwindigkeit (6.0 km/s) bis in etwa 70 km Tiefe ausgegangen werden, ohne daß eine Moho zu erkennen ist. Im Backarc sind der Abfall der Moho von 40 km unter dem Subandin auf etwa 70 km am Ostrand des Altiplano sowie Zonen hoher Geschwindigkeit (6.8 km/s) in der Oberkruste der Ostkordillere mit darunterliegender LVZ die wichtigsten Merkmale der Krustenstruktur. Die Überschiebungsstrukturen und die heutige Krustenmächtigkeit im Backarc konnten durch eine tektonische Modellierung ("crustal balancing") mit einer Verkürzung von 320 km seit der Oberkreide und einer Ausgangskrustenmächtigkeit von 35 km modelliert werden. Die Bereiche hoher Geschwindigkeit in der Ostkordillere werden als Unterkrustenmaterial interpretiert, das nach Osten auf das Vorland überschoben wurde und damit zu einer Krustenverdopplung geführt hat. Etwa 20% des heutigen Krustenvolumens, entsprechend der tieferen Kruste im Forearc und unter dem magmatischen Bogen, kann, unter der Annahme von 320 km tektonischer Verkürzung seit der Oberkreide, nicht durch tektonische Krustenverdickung erklärt werden. Diese tiefere Kruste, die durch extreme Krustenparameter wie geringe seismische Geschwindigkeit und hohe elektrische Leitfähigkeit gekennzeichnet ist, muß als Mischzone von Material unterschiedlicher Herkunft angesehen werden, wobei tektonisch erodiertes Material vom Kontinental rand, serpentinisiertes Mantelmaterial sowie magmatisches Material am Aufbau dieses Krustenstockwerkes beteiligt sein können. Südlich von 21 °S ändern sich die tektonischen Strukturen und die Krustenmächtigkeit und sowohl die Verkürzungsbeträge als auch das gesamte Krustenvolumen gehen nach Süden, im Bereich der flachen Subduktion, deutlich zurück. Für den lithosphärischen Mantel muß eine Verkürzung um den gleichen Betrag wie für die Kruste vorausgesetzt werden, die einen Transport dieses Materials in tiefere Mantelzonen erforderlich macht.

Description: The object of this paper is the evaluation and interpretation of a net of mainly reversed seismic refraction profiles measured from 1982 to 1989 to investigate the crustal structure of the Central Andes. The derived crustal structure and crustal thickness was then modelled by a tectonic balancing method. A strong variation of the crustal parameters has been derived by three N-S profiles in the Coastal Cordillera, the Precordillera and the Argentine Puna, three W-E profiles from the coast to the Puna (24 °S), to the Western Cordillera (22 °S) and crossing the entire Andes up to the Bolivian Chaco (21 °S) as well as by profiles and fan recordings referring to the Chuquicamata copper mine. A clear discontinuity at 40 km depth below the Coastal Cordillera is interpreted as the Moho of the subducted oceanic Nazca plate. The plate dips to the east and can be observed by the seismic refraction data up to the Longitudinal Valley and possibly up to the Precordillera. The continental crust in the forearc has a very high average velocity of 6.6 km/s, descending to 6.2 km/s in the Precordillera. A division into a high velocity upper and middle crust, representing the mesozoic crust in this area, and a deeper crust, mainly represented by low velocity zones (LVZ), can be done. Only in the southern profile of the eastern adjacent Western Cordillera, the actual magmatic arc, a crust/mantle boundary can be observed at 60 km depth. Further north a strong absorption of the seismic waves must be assumed that leads to a low average velocity (6.0 km/s) down to 70 km depth, but a Moho is not observed. In the backarc, a dip of the Moho from 40 km below the Subandean Ranges to about 70 km at the eastern margin of the Altiplano as well as zones of high velocities (6.8 km/s) in the upper crust of the Eastern Cordillera followed by a thick LVZ are the main features of the crustal structure. The thrust structures and the actual crustal thickness in the backarc have been modelled by a crustal balancing with 320 km of shortening since the Upper Cretaceous and an initial crustal thickness of 35 km. The areas of high velocity in the Eastern Cordillera are interpreted as lower crustal material overthrusted upon the foreland and which thereby produced a crustal doubling. The deeper crust below the forearc and the magmatic arc, about 20% of the actual crustal volume, cannot be explained by the crustal shortening. This deeper crust must be seen as a mixture of material of different provenience as tectonically eroded material from the continental margin, transformed mantle material and magmatic underplated material. South of 21 °S the tectonic structures as well as the crustal thickness change in a way that the shortening values and the total crustal volume decrease strongly towards the south where the subduction angle tends to be subhorizontal. The same amount of shortening must be assumed for the mantle lithosphere which requires a transport of material into the deeper mantle.

Description: thesis

Description: DFG, SUB Göttingen

Description: Es wird ein 3D-Dichtemodell der Nördlichen Kalkalpen vorgestellt, das sich auf eine breite Datenbasis von Ergebnissen aus der Gravimetrie, der Reflexionsseismik, der Refraktionsseismik und von Bohrlochmessungen stützen kann. Das Modell erfaßt die oberflächennahen Störmassen durch die Verwendung der Bougueranomalie mit variablem Dichteansatz (Meurers et al., 1989) und berücksichtigt eine Moho, deren Struktur unter Verwendung einer Kombination von direkten und indirekten, gravimetrischen 3D-Verfahren auf der Basis der gravimetrischen und seismischen Ergebnisse berechnet wurde. Zusammen mit den Informationen aus der Reflexionsseismik konnten mit diesem Konzept alle wesentlichen, bekannten Strukturen zwischen der topographischen Oberfläche und der Moho in die Modellierungen integriert werden. Das vorgestellte 3D-Dichtemodell erlaubt eine • Analyse der gravimetrischen Krusten- und Mantel-Effekte, sowie eine • Analyse der Qualität der Bougueranomalie mit variablem Dichteansatz. Voruntersuchungen, die Erstellung der nötigen Hilfsmittel zur Berechnung des 3D-Modells und dessen Diskussion brachten die folgenden Resultate: • Eine Zusammenstellung der im Untersuchungsgebiet vorkommenden Gesteinsdichten, basierend auf Handstücken, Dicht elogs und Ergebnissen der seismischer Teufenwandlung und der statistisch behandelten Geschwindigkeit slogs, wird vorgelegt. • Die 2D-Modellrechnungen im Vorland zeigen, daß Dreieckszonen (triangle zones) gravimetrisch nicht direkt nachweisbar sind. Auch eine altersabhängige Dichteverteilung der einzelnen Molasseeinheiten erzeugen nur sehr geringe gravimetrische Effekte. Die Bausteinschichten sind dagegen in oberflächennaher, steiler Lagerung gravimetrisch auflösbar. Sie können als ’’tektonische Indikatoren” in ein lokales 3D-Modell integriert werden. Im regionalen Rahmen sind sie wegen ihres geringen Schwereeffektes aber nicht erfaßbar. • Für die Nördlichen Kalkalpen wird die gravimetrische Auflösbarkeit geologischer Strukturen untersucht und die Aussagefähigkeit von 2D-Modellrechnungen relativiert. • Die geologischen Interpretationen auf den Profilen Grünten - Landeck und Bad Tölz - Innsbruck stehen im Einklang mit den gravimetrischen Daten. Die 2D-Modellrechnungen fordern für Schwereuntersuchungen in diesem Gebiet die Verwendung der Bougueranomalie mit variablem Dichteansatz und die Berücksichtigung der Moho. • Eine das gesamte Untersuchungsgebiet überdeckende Bougueranomalie mit variablem Dichteansatz wird vorgestellt und anhand des Residualschwerefeldes des 3D-Modells diskutiert. • Die unter Verwendung von Daten aus der Reflexionsseismik, Refraktionsseismik und Gravimetrie berechnete Moho unter den Nördlichen Kalkalpen wird vorgestellt. • Der in der Literatur oft verwendete Dichtekontrast an der Moho von 0.4 g/cm3 ist für das Untersuchungsgebiet nicht realistisch. Die Modellrechnungen führen zu einem Kontrast von 0.22 g/cm3 an der Kruste-Mantel-Grenze. • Eine Trennung der Krusten- und Mantel- Effekte im Untersuchungsgebiet ist nicht mit Wellenlängenfilterungen, sondern nur mittels 3D-Modellrechnungen möglich.

Description: thesis

Description: DFG, SUB Göttingen

Description: Dieser Band enthält 72 Beiträge zu Themengebieten der Physik der festen Erde, des magnetischen und elektrischen Felds der Erde, der Physik der Atmosphäre sowie der Angewandten Geophysik, veröffentlicht durch die Deutsche Geophysikalische Gesellschaft in den Jahren 1928.

Description: 〈html〉 〈body〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0004.pdf"〉Titelseite〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0005.pdf"〉Gezeitenerscheinungen in der Atmosphäre〈/a〉〈br〉(Bartels, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0006.pdf"〉Erdmagnetische Säkularvariation und die Orientation alter Kultbauwerke〈/a〉〈br〉(Wehner, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0007.pdf"〉Über die Tiefenwirkung bei geoelektrischen Potentiallinienmethoden〈/a〉〈br〉(Hummel, J. N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0008.pdf"〉Überblick über den Gang der magnetischen Vermessung der Ostsee〈/a〉〈br〉(v. Gernet, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0009.pdf"〉Die Wirkung der Kontinente und Ozeane auf die Differenz 〈i〉B – A〈/i〉 der Hauptträgheitsmomente der Erde im Äquator〈/a〉〈br〉(Gutenberg, B.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0011.pdf"〉Bemerkungen zu H. v. Iherings Kritik der Theorien der Kontinentverschiebungen und der Polwanderungen〈/a〉〈br〉(Wegener, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0012.pdf"〉Berichtigung〈/a〉〈br〉(Jung, K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0013.pdf"〉Illustration〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0014.pdf"〉Über die Polhöhenschwankungen infolge der Lorentz-Kontraktion der Erde〈/a〉〈br〉(Courvoisier, L.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0015.pdf"〉Zum Uhrvergleich auf drahtlosem Wege nach der Koinzidenzhörmethode〈/a〉〈br〉(Martin, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0016.pdf"〉Physikalische Grundlagen einer neuen geoelektrischen Aufschlußmethode〈/a〉〈br〉(Hummel, J. N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0017.pdf"〉Untersuchung der Potentialverteilung für einen speziellen Fall im Hinblick auf geoelektrische Potentiallinienverfahren〈/a〉〈br〉(Hummel, J. N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0018.pdf"〉Mächtigkeitsbestimmung von Deckschichten über Spalten durch Radioaktivitätsmessungen〈/a〉〈br〉(Koenigsberger, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0019.pdf"〉Zur Frage der regionalen, magnetischen Anomalien Deutschlands, insbesondere derjenigen Norddeutschlands〈/a〉〈br〉(Reich, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0021.pdf"〉Untersuchungen über die seismische Bodenunruhe kurzer Periode〈/a〉〈br〉(Schneider, W.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0022.pdf"〉Zur Theorie elektrischer Bodenforschung〈/a〉〈br〉(Heine, W.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0023.pdf"〉Emil Wiechert †〈/a〉〈br〉(Angenheister, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0024.pdf"〉Die topographische Reduktion bei Drehwagenbeobachtungen〈/a〉〈br〉(Numerov, B.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0025.pdf"〉Angewandte Seismik (Zusammenfassender Bericht über Arbeiten von 1921 bis 1928)〈/a〉〈br〉(v. Schmidt, O.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0027.pdf"〉Le problème des microséismes à groupes〈/a〉〈br〉(Gherzi, E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0028.pdf"〉Zur Empfindlichkeitsbestimmung von magnetischen Variometern und zur Eichung der magnetischen Felder von Spulen〈/a〉〈br〉(Koenigsberger, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0029.pdf"〉Die Schrumpfungsgeschwindigkeit des Erdradius aus astronomischen Beobachtungen〈/a〉〈br〉(Meyermann, B.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0030.pdf"〉Über eine Verbindung zwischen den mondentägigen und den sonnentägigen Variationen der magnetischen Deklination〈/a〉〈br〉(Egedal, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0031.pdf"〉Die Zone der anormalen Hörbarkeit im kleinen〈/a〉〈br〉(Hiller, W.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0032.pdf"〉Mitteilungen〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0033.pdf"〉Ein graphisches Verfahren für Drehwagenmessungen zur Berechnung der Geländewirkung und der Wirkung beliebig gestalteter Massenkörper〈/a〉〈br〉(Haalck, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0035.pdf"〉Beiträge zur geoelektrischen Methode〈/a〉〈br〉(Hummel, J. N.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0036.pdf"〉Zum Uhrvergleich auf drahtlosem Wege nach der Koinzidenzhörmethode〈/a〉〈br〉(Mahnkopf, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0037.pdf"〉Berichtigung〈/a〉〈br〉(Meyermann, B.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0038.pdf"〉Zur Frage nach der Ursache von lokalen gravimetrischen und erdmagnetischen Störungen und ihre wechselseitigen Beziehungen〈/a〉〈br〉(Haalck, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0040.pdf"〉Gemeinschaftliche Arbeit zwischen Seismologen und Baufachmann zur Verringerung von Erdbebenschäden〈/a〉〈br〉(Briske, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0042.pdf"〉Feldapparatur zur Registrierung von Zeitzeichen〈/a〉〈br〉(Köhler, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0043.pdf"〉Über die Schmidtsche Methode der Bestimmung der Parameter von Stabmagneten〈/a〉〈br〉(Bock, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0046.pdf"〉Referate der Vorträge auf der Tagung der Deutschen Geophysikalischen Gesellschaft in Hamburg vom 19. bis 21. September 1928〈/a〉〈br〉(Koenigsberger, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0048.pdf"〉Die Seismizität der Ozeane und Kontinente〈/a〉〈br〉(Tams, E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0049.pdf"〉Bodenunruhe durch Brandung und durch Frost〈/a〉〈br〉(Gutenberg, B.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0050.pdf"〉Beitrag zur Schallausbreitung in der Atmospähre〈/a〉〈br〉(Kölzer, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0051.pdf"〉Das Magnetfeld einer elektrischen Strömung im anisotropen leitenden Halbraum〈/a〉〈br〉(Müller, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0052.pdf"〉Die geführten elastischen Zweimittel-Wellen〈/a〉〈br〉(Uller, K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0053.pdf"〉Vom Jahre 1922 an im südlichen Norwegen aufgenommene Nordlichtphotogramme〈/a〉〈br〉(Störmer, C.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0055.pdf"〉Zur Frage nach der Ursache von lokalen gravimetrischen und erdmagnetischen Störungen und ihre wechselseitigen Beziehungen〈/a〉〈br〉(Haalck, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0057.pdf"〉Vorträge, gehalten auf der Tagung der Deutschen Geophysikalischen Gesellschaft vom 19. bis 21. September 1928〈/a〉〈br〉(Seilkopf, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0060.pdf"〉Statistische Mechanik der Atmosphäre〈/a〉〈br〉(Baur, F.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0061.pdf"〉Das Schwadorfer Beben vom 8. Oktober 1927〈/a〉〈br〉(Conrad, V.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0062.pdf"〉Das Periodogramm der internationalen erdmagnetischen Charakterzahlen〈/a〉〈br〉(Wenzel Pollak, L.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0064.pdf"〉Der Stand der erdmagnetischen Forschung〈/a〉〈br〉(Schmidt, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0065.pdf"〉Magnetische Anomalien im westlichen Mecklenburg〈/a〉〈br〉(Schuh, F.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0066.pdf"〉Bemerkungen zur numerischen und graphischen Behandlung der Krümmungsgröße〈/a〉〈br〉(Jung, K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0067.pdf"〉Der Wasserhaushalt der Antarktis in der Eiszeit〈/a〉〈br〉(Meinardus, W.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0068.pdf"〉Übersicht über Neuerscheinungen〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0069.pdf"〉Vortrage, gehalten auf der Tagung der Deutschen Geophysikalischen Gesellschaft vom 19. bis 21. September 1928〈/a〉〈br〉(Tams, E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0071.pdf"〉Über kartographische Darstellung der Seismizität〈/a〉〈br〉(Renquist, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0072.pdf"〉Ergebnisse von Pilotaufstiegen im Gebiete von Island〈/a〉〈br〉(Georgi, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0073.pdf"〉Referat über die Polarfront- und Äquatorialfronttheorien〈/a〉〈br〉(Stüve, G.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0074.pdf"〉Die Messung der Horizontal- und der Vertikalintensität mit dem Magnetron〈/a〉〈br〉(Rössiger, M.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0075.pdf"〉Untersuchungen über die lokalen Schwankungen des Erdpotentials〈/a〉〈br〉(Stoppel, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0076.pdf"〉Klima und Klimatafel von Hamburg〈/a〉〈br〉(Perlewitz, P.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0077.pdf"〉Neue Ergebnisse über die Struktur des Windes (Vorläufige Mitteilung)〈/a〉〈br〉(Schmidt, W.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0079.pdf"〉Lokale und regionale magnetische Anomalien in Schleswig-Holstein〈/a〉〈br〉(Reich, H.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0080.pdf"〉Die optische Station in Simferopol〈/a〉〈br〉(Tichanowsky, J.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0081.pdf"〉Das Strömungssystem der Luft über dem tropischen Atlantischen Ozean nach den Höhenwindmessungen der Meteor-Expedition〈/a〉〈br〉(Kuhlbrodt, E.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0082.pdf"〉Ergebnisse und Aufgaben der meteorologischen Strahlungsmessungen〈/a〉〈br〉(Süring, R.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0083.pdf"〉Ergebnisse von Drehwaagemessungen in Schlewig-Holstein〈/a〉〈br〉(Jung, K.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0085.pdf"〉Aufsätze〈/a〉〈br〉(Lotze, F., Brockamp, B., Haalck, H., Myrbach, O., Whipple, Cabannes, J., Dufay, J., Gherzi, E., Pochettino, A., Rostagni, A.)〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0096.pdf"〉Mitteilungen〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0097.pdf"〉Autorenverzeichnis〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0098.pdf"〉Sachverzeichnis〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0099.pdf"〉Literaturverzeichnis〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0100.pdf"〉Geophysikalische Berichte〈/a〉〈/li〉 〈li〉〈a href="https://gdz.sub.uni-goettingen.de/download/pdf/PPN101433392X_0004/LOG_0101.pdf"〉Register der Goephysikalische Berichte〈/a〉〈/li〉 〈/body〉 〈/html〉

Description: research

Description: DGG, DFG, SUB Göttingen

Description: Unpublished

Description: Not Known

Description: Hypoxia (O2 〈 2 mg/L) driven by eutrophication in estuaries and shelves is a worldwide expanding problem. The role of organic matter (OM) inputs is emerging as an important contributor to this issue, beside the well-known implication of inorganic nutrients. The St. Lawrence Estuary, one of the largest and deepest estuarine system in the world is facing strong persistent and increasing hypoxia. In this context, transport and exchange of particulate and dissolved organic matter (POM and DOM, respectively) were investigated as a first step to understand their implication in hypoxia. Tributaries and Gulf contributions were compared to St. Lawrence Estuary inventories for the spring freshet (May), the summer low-flow (August), and the fall-mixing (October). Furthermore, changes in OM ratios were examined along the estuarine gradient from the upper St. Lawrence Estuary (USLE), downstream of the maximum turbidity zone, to the lower estuary (LSLE). For the USLE, net transport was always positive and net export/loading ratios suggested that 64–90% of POM and 30–63% of DOM were either retained or transformed during its course from tributaries to LSLE. Net transport from the USLE toward the LSLE was 3–13 fold more important in May than in August or October. For the LSLE, net transport to the Gulf was generally negative meaning that OM production was the dominating proces. The extremely high net export/loading ratios in August indicate that POM production was 28.8 to 41.4 times the combined inputs of tributaries and Gulf. Net export/loading ratios remained superior to one during May and October (1.7–9.4) for the LSLE. Changes along the upstream–downstream continuum were seen for POM, with a steady increase relative to total suspended matter from 7.3% to 50.2%, but they were not observed for DOM, for which no obvious trends were detected. Our results highlight the importance of explicitly considering OM in eutrophication monitoring programs of the St. Lawrence Estuary, as the mineralisation of a portion of the large OM pool size could influence our understanding of hypoxia and acidification of the deep waters of LSLE.

Description: Published

Description: Refereed

Description: Better integration of climate action and sustainable development can help enhance the ambition of the next nationally determined contributions, as well as implementation of the Sustainable Development Goals. Governments should use this year as an opportunity to emphasize the links between climate and sustainable development.

Description: Floristic taxonomic research, looking for constant differences between species, is a very time-consuming and slow process. The flora of the Malay Archipelago is estimated to have 45,000 vascular plant species and the Flora Malesiana project that describes them has completed c. 1/3rd in 75 years. Presently, the flora is heavily threatened because of land use and climate change. We have to speed up the flora writing to understand what will be threatened and how to counter the threats. Innovation using Next Generation Sequencing of DNA to find the species in combination with Image Recognition might help to increase speed. Another aspect is cooperation, more international scientists should be involved, also students and citizens via citizen science projects. Citizens can help to gather information (observations and collecting). Once the flora is better known, monitoring of the flora by regular inventories (done by non-scientists in the Netherlands) helps to see which plants are threatened or become plagues and causes can then be investigated. Monitoring will help to change energy consumption (no more fossil energy), agriculture, industry, and living: improve our climate, and save the planet.

Description: AlUla region in Saudi Arabia has a rich history regarding mankind, local wildlife, and fertility islands suitable for leguminous species, such as the emblematic Vachellia spp. desert trees. In this region, we investigated the characteristics of desert legumes in two nature reserves (Sharaan and Madakhil), at one archaeological site (Hegra), and in open public domains et al. Ward and Jabal Abu Oud. Biological nitrogen fxation (BNF), isotopes, and N and C contents were investigated through multiple lenses, including parasitism, plant tissues, species identifcation, plant maturity, health status, and plant growth. The average BNF rates of 19 Vachellia gerrardii and 21 Vachellia tortilis trees were respectively 39 and 67%, with low signs of inner N content fuctuations (2.10–2.63% N) compared to other co-occurring plants. The BNF of 23 R. raetam was just as high, with an average of 65% and steady inner N contents of 2.25±0.30%. Regarding parasitism, infected Vachellia trees were unfazed compared to uninfected trees, thereby challenging the commonly accepted detrimental role of parasites. Overall, these results suggest that Vachellia trees and R. raetam shrubs exploit BNF in hyper-arid environments to maintain a high N content when exposed to parasitism and grazing. These fndings underline the pivotal role of plant-bacteria mutualistic symbioses in desert environments. All ecological traits and relationships mentioned are further arguments in favor of these legumes serving as keystone species for ecological restoration and agro-silvo-pastoralism in the AlUla region.

Description: Computer vision-based wood identification has been successfully applied to recognize tree species using digital images of wood sections or surfaces. However, this image-to-species approach can only recognize a limited number of species due to two main reasons: 1) the lack of a good reference database requiring high-quality standardized images from multiple individuals of hundreds or even thousands of traded timber species, and 2) species not included in the reference database cannot be identified without expert knowledge. Another bottleneck is that the feature extraction process used by these species recognition approaches is a black box, thereby creating a discrepancy between machine learning features and wood anatomical features. This discrepancy prevents wood anatomists from understanding how these machine-learning algorithms work. Here, we survey currently existing methods used in feature extraction, classification, and deep learning methods applied in wood identification along with their pitfalls and opportunities. As an example of how the field could move forward, we launch the idea of building an image-to-features-to-species identification approach based on microscopic wood images as well as text files comprising wood anatomical descriptions. If we can manage machine learning-based algorithms to recognize the main wood anatomical traits that experts use to identify species in a (semi-)automated way, this would boost wood identification in two ways: (1) extensive reference databases for each species would become less crucial as the databases are ordered at the trait level, (2) timber identification would become more feasible for species that have not yet been included in the reference database as long as wood anatomical descriptions are available.

Description: Novel species of fungi described in this study include those from various countries as follows: Australia, Austroboletus asper on soil, Cylindromonium alloxyli on leaves of Alloxylon pinnatum, Davidhawksworthia quintiniae on leaves of Quintinia sieberi, Exophiala prostantherae on leaves of Prostanthera sp., Lactifluus lactiglaucus on soil, Linteromyces quintiniae (incl. Linteromyces gen. nov.) on leaves of Quintinia sieberi, Lophotrichus medusoides from stem tissue of Citrus garrawayi, Mycena pulchra on soil, Neocalonectria tristaniopsidis (incl. Neocalonectria gen. nov.) and Xyladictyochaeta tristaniopsidis on leaves of Tristaniopsis collina, Parasarocladium tasmanniae on leaves of Tasmannia insipida, Phytophthora aquae-cooljarloo from pond water, Serendipita whamiae as endophyte from roots of Eriochilus cucullatus, Veloboletus limbatus (incl. Veloboletus gen. nov.) on soil. Austria, Cortinarius glaucoelotus on soil. Bulgaria, Suhomyces rilaensis from the gut of Bolitophagus interruptus found on a Polyporus sp. Canada, Cantharellus betularum among leaf litter of Betula, Penicillium saanichii from house dust. Chile, Circinella lampensis on soil, Exophiala embothrii from rhizosphere of Embothrium coccineum. China, Colletotrichum cycadis on leaves of Cycas revoluta. Croatia, Phialocephala melitaea on fallen branch of Pinus halepensis. Czech Republic, Geoglossum jirinae on soil, Pyrenochaetopsis rajhradensis from dead wood of Buxus sempervirens. Dominican Republic, Amanita domingensis on litter of deciduous wood, Melanoleuca dominicana on forest litter. France, Crinipellis nigrolamellata (Martinique) on leaves of Pisonia fragrans, Talaromyces pulveris from bore dust of Xestobium rufovillosum infesting floorboards. French Guiana, Hypoxylon hepaticolor on dead corticated branch. Great Britain, Inocybe ionolepis on soil. India, Cortinarius indopurpurascens among leaf litter of Quercus leucotrichophora. Iran, Pseudopyricularia javanii on infected leaves of Cyperus sp., Xenomonodictys iranica (incl. Xenomonodictys gen. nov.) on wood of Fagus orientalis. Italy, Penicillium vallebormidaense from compost. Namibia, Alternaria mirabibensis on plant litter, Curvularia moringae and Moringomyces phantasmae (incl. Moringomyces gen. nov.) on leaves and flowers of Moringa ovalifolia, Gobabebomyces vachelliae (incl. Gobabebomyces gen. nov.) on leaves of Vachellia erioloba, Preussia procaviae on dung of Procavia capensis. Pakistan, Russula shawarensis from soil on forest floor. Russia, Cyberlindnera dauci from Daucus carota. South Africa, Acremonium behniae on leaves of Behnia reticulata, Dothiora aloidendri and Hantamomyces aloidendri (incl. Hantamomyces gen. nov.) on leaves of Aloidendron dichotomum, Endoconidioma euphorbiae on leaves of Euphorbia mauritanica, Eucasphaeria proteae on leaves of Protea neriifolia, Exophiala mali from inner fruit tissue of Malus sp., Graminopassalora geissorhizae on leaves of Geissorhiza splendidissima, Neocamarosporium leipoldtiae on leaves of Leipoldtia schultzii, Neocladosporium osteospermi on leaf spots of Osteospermum moniliferum, Neometulocladosporiella seifertii on leaves of Combretum caffrum, Paramyrothecium pituitipietianum on stems of Grielum humifusum, Phytopythium paucipapillatum from roots of Vitis sp., Stemphylium carpobroti and Verrucocladosporium carpobroti on leaves of Carpobrotus quadrifolius, Suttonomyces cephalophylli on leaves of Cephalophyllum pilansii. Sweden, Coprinopsis rubra on cow dung, Elaphomyces nemoreus from deciduous woodlands. Spain, Polyscytalum pini-canariensis on needles of Pinus canariensis, Pseudosubramaniomyces septatus from stream sediment, Tuber lusitanicum on soil under Quercus suber. Thailand, Tolypocladium flavonigrum on Elaphomyces sp. USA, Chaetothyrina spondiadis on fruits of Spondias mombin, Gymnascella minnisii from bat guano, Juncomyces patwiniorum on culms of Juncus effusus, Moelleriella puertoricoensis on scale insect, Neodothiora populina (incl. Neodothiora gen. nov.) on stem cankers of Populus tremuloides, Pseudogymnoascus palmeri from cave sediment. Vietnam, Cyphellophora vietnamensis on leaf litter, Tylopilus subotsuensis on soil in montane evergreen broadleaf forest. Morphological and culture characteristics are supported by DNA barcodes.

Description: A newly built versatile device for mode I fracture toughness measurement is presented. To test this apparatus, measurements have been conducted on two crystalline rocks, the Aue Granite and the Äspö Diorite, and two chalks from the Paris basin, Obourg and Ciply chalks. The fracture toughness KIC can be measured with two different testing procedures, the Semi-Circular Bend (SCB) and the Straight Edge Cracked Round Bar Bend (SECRBB) methods, both known for the easiness of the notched sample preparation. For the SCB tests, ultrasonic sensors were mounted at the sample surface to monitor changes in P-wave velocity and record acoustic emission activity. Our results are in reasonably good agreement with published data on the same rocks. The SECRBB test provides values of the fracture toughness 37% higher compared to the SCB test for the Obourg chalk. This discrepancy may be explained by a sample size effect. The fracture toughness of water saturated chalks is strongly reduced compared to that of the dry chalks by almost 50%. This shows that fracture toughness is a valuable parameter to assess the importance of water weakening in porous rocks.

Description: The recent deliverable describes the development and the characteristics of the European Fluid Atlas (EFA) created in the frame of the REFLECT project by University of Miskolc. In the Atlas, formerly existing and newly measured data of geothermal fluids are visualised. Fluid data were collected from 21 European countries. The layers provide point feature information presented on a base map, including geography, geology, and depth range, as well as physical, chemical and microbial properties of fluids. Data of wells, rocks and reservoirs are also available. The focus is on fluids used for electricity generation (〉 100 °C), but data from heat projects are also included. A free and open-source cross-platform is used for the visualisation, in which the geographic information system provides the environment to view, edit and analyse geospatial data. The interface includes query and filtering tools to explore the database with a map-based visualization. The query results can be downloaded as an excel worksheet. By selecting the entire dataset, the downloaded report contains all the data published on EFA.

Description: Data presented here were collected between Januar 2021 to November 2021 within the research unit DynaCom (Spatial community ecology in highly dynamic landscapes: From island biogeography to metaecosystems, https://uol.de/dynacom/) of the Universities of Oldenburg, Göttingen, and Münster, the iDiv Leipzig and the Nationalpark Niedersächsisches Wattenmeer. Experimental islands and saltmarsh enclosed plots were created in the back barrier tidal flat and in the saltmarsh zone of the island of Spiekeroog. Sediment samples for the determination of pH, water content and loss on ignition were taken bi-/monthly in surface sediments (0-3 cm depth). Samples were measured in the laboratory within two months after sampling.

Description: The dataset includes solid-phase geochemistry data of sediment cores from Site C0023 (Hole A) that was recovered during International Ocean Discovery Program (IODP) Expedition 370 in the Nankai Trough offshore Japan in the Pacific Ocean (Drilling vessel Chikyu). Site C0023 was established on 17 September 2016. Coring terminated on 3 November 2016. Solid-phase geochemistry data include bulk iron (Fe), sulfur (S) and aluminum (Al) contents as well as chromium reducible sulfur (CRS). The bulk element contents were determined by performing total acid digestions (dissolution of dry sediment in a mixture of 65% HNO3 (3 ml), 30% HCl (2 ml), and 40% suprapur® HF (0.5 ml) in a CEM Mars Xpress microwave system). Sequential iron extractions were performed after Poulton and Canfield (2005) and Henkel et al. (2016) to quantify the reactive iron pools (Fe aca, sodium acetate extraction; Fe hyam, hydroxylamine-HCl extraction; Fe di-ct, sodium dithionite/sodium citrate extraction; Fe oxa, oxalate/oxalic acid extraction). We further determined the amounts of Al (Al aca, Al hyam, Al di-ct, Al oxa) and silicon (Si; Si aca, Si hyam, Si di-ct, Si oxa) released by the different extraction steps for a selection of samples. All elemental contents (except for CRS) were measured by inductively coupled plasma – optical emission spectroscopy (ICP-OES; iCAP 7400, Thermo Fisher Scientific Inc.). CRS was extracted using a CrCl2 solution after Canfield et al. (1986) and Zhabina & Volkov (1978). All values are given in wt%.

Description: Time-series data of physical & biological oceanography, nutrient biogeochemistry, molecular biology and carbon/particle export were obtained from mooring HG-EGC-5 in the Fram Strait in July 2018 - August 2019 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV POLARSTERN expedition PS114, and recovered during PS121. The attached archive contains raw data files of three Seabird SBE37 microcats (nominal depths: 72m, 241m, 508m; sampling interval 1h), three AADI RCM11 current meters (nominal depths: 79m, 248m, 511m; sampling interval 1h), one AADI Seaguard current meter (nominal depth: 987m, sampling interval 1h), one Wetlabs ECO PAR sensor (nominal depth: 72m; sampling interval 1h), one Wetlabs ECO Triplet fluorometer (nominal depth: 72m; sampling interval 2h), two Satlantics SUNA nitrate sensors (nominal depths: 72m, 241m; sampling interval 4h), one Sunburst SAMI-pCO2 sensor (nominal depth: 241m; sampling interval 1h) and two Sunburst SAMI-pH sensors (nominal depths: 72m, 241m; sampling interval 3h). One Sunburst SAMI-pCO2 sensor (72m) was flooded and all data was lost. The mooring also included two McLane RAS water samplers (nominal depths: 72m, 241m) and one sediment trap (nominal depth: 504m). Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable.

Description: Arctic warming increases the degradation of permafrost soils but little is known about floodplain soils and other permafrost soils in the permafrost region. This dataset present soil properties from twelve analyzed cores located in the northeastern Siberian Lena River Delta within the continuous permafrost zone in northern Yakutia, Russia that were sampled in 2018. The cores represent intact yedoma, yedoma thaw slumps, and floodplain profiles. The soil coring and sampling was carried out in August 2018 for a total of 30 soil cores, 35 soil profiles, and 341 sediment samples. First, vegetation and other characteristics of the plots were described. Then, the active layer soils were excavated, described, and sampled with a fixed volume cylinder (250 cm³). Then the permafrost layers were sampled with a modified, snow, ice, and permafrost (SIPRE) auger to a depth of 1 m (core diameter of 7.62 cm) and visually described in their characteristics. Each core was divided into subsamples with 5-10 cm length according to its facies horizons, transported frozen to Alfred Wegener Institute in Potsdam, and stored at -20 °C until analysis. A subset of these sediment samples (n=105 from 12 cores) were later analyzed in the laboratory for physical and chemical properties; this data is presented here. The analysis from these samples includes: water content, dry bulk density, gravimetric ice content, pH, conductivity, total organic carbon content, total inorganic carbon content, total carbon content, total nitrogen content, carbon density, TOC storage, and TN storage. Selected samples were further analyzed for radiocarbon and grain size analysis.

Description: Time-series data of physical oceanography and ocean current velocities were obtained from mooring SCO2-1 in the Fram Strait from Aug 2018 to Aug 2022. The mooring was deployed during RV MARIA S. MERIAN expedition MSM76 and recovered during RV POLARSTERN expedition PS131. The attached archive contains raw data files of two Seabird SBE16 SeaCATs (nominal depths: 595m, 800m; sampling interval 1h), two SBE37 MicroCATs (nominal depths: 666m, 726m; sampling interval 10m), three SBE56 temperature logger (nominal depths: 626m, 696m, 766m; sampling interval 20s), one RDI Longranger ADCP (nominal depth: 796m; sampling interval 2h) and one AADI RCM11 current meter (nominal depth: 801m; sampling interval 2h). Auxiliary information such as sensor calibration sheets, mooring diagrams, and schedule files are also provided, if applicable. The ADCP had issues and only recorded data at irregular intervals up to several days.

Description: Time-series data of physical oceanography and ocean current velocities were obtained from mooring F3-19 in the Fram Strait from July 2020 to July 2022 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV MARIA S. MERIAN expedition MSM93 and recovered during RV POLARSTERN expedition PS131. The attached archive contains raw data files of three Seabird SBE37 MicroCATs (nominal depths: 49m, 245m, 764m; sampling interval 30m/1h), one RDI Longranger ADCP (nominal depth: 406m; sampling interval 2h) and two Nortek Aquadopp current meter (nominal depths: 763m, 1070m; sampling interval 1h). Auxiliary information such as sensor calibration sheets, mooring diagrams, and schedule files are also provided, if applicable.